Module:Namespace detect

Module documentation This module is copied from the English Wikipedia page en:Module:Namespace detect. It has no documentation, and relevant information may be found at the corresponding English Wikipedia documentation page. For more details see the editing history of the module. The above documentation is transcluded from Module:Namespace detect/doc.

---

--[[
--------------------------------------------------------------------------------
--                                                                            --
--                            NAMESPACE DETECT                                --
--                                                                            --
-- This module implements the {{namespace detect}} template in Lua, with a    --
-- few improvements: all namespaces and all namespace aliases are supported,  --
-- and namespace names are detected automatically for the local wiki. The     --
-- module can also use the corresponding subject namespace value if it is     --
-- used on a talk page. Parameter names can be configured for different wikis --
-- by altering the values in the "cfg" table in                               --
-- Module:Namespace detect/config.                                            --
--                                                                            --
--------------------------------------------------------------------------------
--]]

local data = mw.loadData('Module:Namespace detect/data')
local argKeys = data.argKeys
local cfg = data.cfg
local mappings = data.mappings

local yesno = require('Module:Yesno')
local mArguments -- Lazily initialise Module:Arguments
local mTableTools -- Lazily initilalise Module:TableTools
local ustringLower = mw.ustring.lower

local p = {}

local function fetchValue(t1, t2)
	-- Fetches a value from the table t1 for the first key in array t2 where
	-- a non-nil value of t1 exists.
	for i, key in ipairs(t2) do
		local value = t1[key]
		if value ~= nil then
			return value
		end
	end
	return nil
end

local function equalsArrayValue(t, value)
	-- Returns true if value equals a value in the array t. Otherwise
	-- returns false.
	for i, arrayValue in ipairs(t) do
		if value == arrayValue then
			return true
		end
	end
	return false
end

function p.getPageObject(page)
	-- Get the page object, passing the function through pcall in case of
	-- errors, e.g. being over the expensive function count limit.
	if page then
		local success, pageObject = pcall(mw.title.new, page)
		if success then
			return pageObject
		else
			return nil
		end
	else
		return mw.title.getCurrentTitle()
	end
end

-- Provided for backward compatibility with other modules
function p.getParamMappings()
	return mappings
end

local function getNamespace(args)
	-- This function gets the namespace name from the page object.
	local page = fetchValue(args, argKeys.demopage)
	if page == '' then
		page = nil
	end
	local demospace = fetchValue(args, argKeys.demospace)
	if demospace == '' then
		demospace = nil
	end
	local subjectns = fetchValue(args, argKeys.subjectns)
	local ret
	if demospace then
		-- Handle "demospace = main" properly.
		if equalsArrayValue(argKeys.main, ustringLower(demospace)) then
			ret = mw.site.namespaces[0].name
		else
			ret = demospace
		end
	else
		local pageObject = p.getPageObject(page)
		if pageObject then
			if pageObject.isTalkPage then
				-- Get the subject namespace if the option is set,
				-- otherwise use "talk".
				if yesno(subjectns) then
					ret = mw.site.namespaces[pageObject.namespace].subject.name
				else
					ret = 'talk'
				end
			else
				ret = pageObject.nsText
			end
		else
			return nil -- return nil if the page object doesn't exist.
		end
	end
	ret = ret:gsub('_', ' ')
	return ustringLower(ret)
end

function p._main(args)
	-- Check the parameters stored in the mappings table for any matches.
	local namespace = getNamespace(args) or 'other' -- "other" avoids nil table keys
	local params = mappings[namespace] or {}
	local ret = fetchValue(args, params)
	--[[
	-- If there were no matches, return parameters for other namespaces.
	-- This happens if there was no text specified for the namespace that
	-- was detected or if the demospace parameter is not a valid
	-- namespace. Note that the parameter for the detected namespace must be
	-- completely absent for this to happen, not merely blank.
	--]]
	if ret == nil then
		ret = fetchValue(args, argKeys.other)
	end
	return ret
end

function p.main(frame)
	mArguments = require('Module:Arguments')
	local args = mArguments.getArgs(frame, {removeBlanks = false})
	local ret = p._main(args)
	return ret or ''
end

function p.table(frame)
	--[[
	-- Create a wikitable of all subject namespace parameters, for
	-- documentation purposes. The talk parameter is optional, in case it
	-- needs to be excluded in the documentation.
	--]]
	
	-- Load modules and initialise variables.
	mTableTools = require('Module:TableTools')
	local namespaces = mw.site.namespaces
	local cfg = data.cfg
	local useTalk = type(frame) == 'table' 
		and type(frame.args) == 'table' 
		and yesno(frame.args.talk) -- Whether to use the talk parameter.
	
	-- Get the header names.
	local function checkValue(value, default)
		if type(value) == 'string' then
			return value
		else
			return default
		end
	end
	local nsHeader = checkValue(cfg.wikitableNamespaceHeader, 'Namespace')
	local aliasesHeader = checkValue(cfg.wikitableAliasesHeader, 'Aliases')

	-- Put the namespaces in order.
	local mappingsOrdered = {}
	for nsname, params in pairs(mappings) do
		if useTalk or nsname ~= 'talk' then
			local nsid = namespaces[nsname].id
			-- Add 1, as the array must start with 1; nsid 0 would be lost otherwise.
			nsid = nsid + 1 
			mappingsOrdered[nsid] = params
		end
	end
	mappingsOrdered = mTableTools.compressSparseArray(mappingsOrdered)

	-- Build the table.
	local ret = '{| class="wikitable"'
		.. '\n|-'
		.. '\n! ' .. nsHeader
		.. '\n! ' .. aliasesHeader
	for i, params in ipairs(mappingsOrdered) do
		for j, param in ipairs(params) do
			if j == 1 then
				ret = ret .. '\n|-'
					.. '\n| <code>' .. param .. '</code>'
					.. '\n| '
			elseif j == 2 then
				ret = ret .. '<code>' .. param .. '</code>'
			else
				ret = ret .. ', <code>' .. param .. '</code>'
			end
		end
	end
	ret = ret .. '\n|-'
		.. '\n|}'
	return ret
end

return p